1. Field of the Invention
The invention refers to a device for the closing and sealing of cable cutout bushings of major diameters, generally of a rectangular shape, as they are usually provided for leading through electrical cables with premounted plugs. The device can be used at interfaces of control enclosures or prefabricated walls and bracket systems in coupling or connecting elements as well as for switching cabinets and enclosures for the closing and sealing of major cable bushings.
2. Description of the Prior Art
In the installation of electrical wires, cables or the like (cables), it is typically necessary to close and form a seal around large cross-section wall openings, generally rectangular in shape, through which cables pass. Frequently, the cables being lead through have plugs already fitted to them.
As the cross-sectional width of the wall openings has to be at least large enough for the plug connectors to pass through, it is usually many times larger than the cross-section of the cables. If a number of cables pass through the same opening, it must be large enough not only for the plug connectors, but also for the relevant number of cables. If such cable access openings are then to be closed over and sealed, devices will be required which hermetically bridge the difference in size between the relatively large opening and the smaller cross-section of the cables, and also form a seal around the rim of the wall opening as well as around the cables.
Devices of this kind display a two-part enclosure divided along the length of the cable opening, such as those shown in German patents DE-OS 27 20 936, DE-GM 89 13 829, and DE 40 20 180 C1. The two parts of the enclosure are fitted to the cables from both sides and are thus joined together enclosing the cables, with a seat attached between the two parts of the enclosure, with foam-rubber sealing rings to form a seal against the cables. The latter, in the nature of things, can only apply a weak sealing pressure, so that it is necessary to provide additional anchorages for the cable inside the enclosure.
Once the enclosure shells have been joined together to form an enclosure around the cables, the cables, already fed through the cable opening to a sufficient length together with their plugs, are passed through the cable opening into the enclosure or into a control cabinet. Only then, are the cables connected to the enclosure for the purpose of covering the cable opening with the enclosure or control cabinet wall. If additional cables are led through the opening later, or if cables have to be replaced, the whole device has to be released from the enclosure or control cabinet wall and the two enclosure halves taken apart. In order to allow cables to be attached to and released from the wall more quickly than is possible with direct screw connections, a device described in DE-GM 89 13 829 possesses a frame element permanently mounted around the opening and representing a mounting for the two-piece enclosure. The holding frame and the enclosure can be easily released with the aid of swivelling or tension bars fastened to the frame and connected to the enclosure with pins. Although such device can be fixed to and removed from the frame quickly in this way, the frame represents additional cost and installation effort and this improvement does nothing to change the difficulties caused by the fact that the enclosure consists of two parts and the installation has to be made in a disadvantageous sequence.
The device described in DE 40 20 180 C1 is characterized by a reduction of the effort required to connect it to the wall. It is fastened by means of a leaf-spring element inserted into the rear side which reaches in through specially shaped protrusions and holds on to the inside of the wall. However, in this case there is still a two-part device which has to be mounted in advance around the cable with the same cost and installation effort as described above.
The problem which the present invention is intended to solve is to create a device of the general prior art kind which displays a similar construction to the familiar devices for leading cables through an opening and creating a seal around them, but for cables without plugs already mounted on them and with equally simple installation characteristics. In other words, a device to solve the problem must be able to be mounted on the enclosure wall, must be filled with a simple opening through which plugs and cables can be passed, and must afterwards create a seal around the cables, thus allowing for the later insertion of additional cables and the replacement and repositioning of cables without the device having to be dismantled. Such needed device should also be capable of being used at all points where the cable opening has to provide a seal around cables with premounted plugs.